Well packer



Jan.14,`1941. RQ BAKER Em 2,228,241'` WELL PACKER Y Jan. 14, 1941.

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R. c. BAKERv E-rAL WELL PACKER Filed May 5, 1939 2 Sheets-Sheet 2described in detail:

Patented Jan. 14, 1941 UNITED STATES PATENT OFFICE WELL PACKERApplication May 5, 1939, Serial No. 271,940

28 Claims.

The present invention relates to well packers, and more particularly to:packers capable of employment in the cementing or repressuring of oilwells, or in testing formations for fluid permeability or breakdownpressures, or in testing casing for holes.

I-t is an object of the present invention to provide an improved wellpacker capable o-f being set, released and reset within the casingwithout the necessity for its withdrawal to the surface of the bore. Ifdesired, ailter the setting of the packer it can be released `andremoved entirely from the casing.

A further object of the invention is to minimize or completely eliminatethe tendency for unintentional setting of a hydraulically operatedpacker within a casing.

Still another object of the invention is to provide an improvedhydraulically operated tripping device for a well packer, permitting theincorporation of 4an efficiently sealed pisto-n of a smaller area, whichconsequently requires a greater unit pressure or fluid head to cause itsmovement against any definite resisting force.

A further object of the invention is to provide a Well packer having aback pressure valve requiring dissimilar degrees of pressure to induceits opening at different stages in the operation of the packer. n

The present invention has other objects that will become apparent from aconsideration of one form in which it is embodied. This form is shown inthe drawings accompanying and forming part `of the presentspecification, and it will now be However, is to be understood that thisdetailed description is not to be taken in a limited sense, since thescope of the invention is best defined by the appended claims.

Referring to the drawings:

Figure 1 is a longitudinal sectional view disclosing one embodiment ofthe invention within a well casing, with the parts in position forrunning th-e device in tne casing;

Figure 2 is a view similar to Figure 1 with the slips and valve assemblyshown in tripped position;

Figure 3 is a view similar to Figure 2 withithe slips shown in fully setposition; and

Figure 4 is a view similar lto Figure 2 with the slips and associ-atedparts disclosed in released position.

The packer includes a generally cylindrical main body II'I, carrying aplurality of circumferentially arranged slips II thereon through themediumof a ring or cage I2, from which pro- (Cl. 16B-12) jects aplurality of radial fingers I3 supporting T-shaped heads I4 extendingfrom the slips. The slips are guided radially of the main body by theengagement of shank portions I5, depending from the heads, with thesides of the fingers I3. The cage or ring I2 is movable downwardlyagainst the action of a helical retractor spring I6 abutting -a flangeI'I extending from the main bodr and an inturned flange or ring I8extending from the cage. Upward movement of the ring is limited by itsengagement wi-th a stop ring I9 xed to the body. The downward movementof the cage will cause its abutment 20 to engage with the upper surfaceof the T-shaped heads I4 on the slips, and move the slips longitudinallyof the body. Each slip I I is provided with a downwardly and outwardlytapered surface 2| engageable with an expander cone 2\2 slidable uponthe main body. It will be noted that the down-ward movement of the slipsin the manner aforementioned will cause their radial outward movement,in view of the engagement `between the cooperable tapered surfaces 2I,23 on the slips and cone, which movement will continue until the wickersor teeth IIa on the exterior of each slip are engaged or embeddedwi'thin the casing C.

Theexpander 22 is supported from 'the main body I0 by a retaining ring24 Ith-readedly or otherwise suitably secu-red to the main body, and

by means of a packing sleeve 25 of rubber or the like secured to boththe cone and retainer. Such securing of the packing sleeve isaccomplished by seating its respective external end anges 2-6, 26 withingrooves or recesses 21, 21 formed Within the cone and the retainer, eachof these grooves being definedV by an inturned flange -28 seating withinan external circumferential groove 29 in the sleeve formed between itsmain portion and outwardly directed flange. 'Ihe rubber packing sleeve25 normally tends lto assume a distended position, urging the cone 22upwardly towards engagement with the slips. l,Howeven this upwardmovement is limited by the abutting of the end of the cone with ltheange I'I provided on the main body.

The slips are set by a trip assembly, including a complementary body 30in the form of a trip nipple or sub, connected to the main body III ofthe packer by a square threaded connection 3|, preferably of lef-t handand fairly steep pitch.

in order to permit the disconnection of the trip assembly from the mainbody. The trip nipple 38 slidably carries a. trip ring 32 -threadedly orotherwise secured to a. trip collar or piston 33, having an inturnedportion forming an annular piston head 34, upon which uid under pressureis adapted .to act after passing -through one or more inlet portsprovided in the nipple. This fluid under pressure will urge the pistondownwardly against the action of a return spring 36 abutting the lowerend of lthe collar at one end, and a stop ring 31 secured to the nippleat its other end. The downward movement of the piston and trip ring islimited by the engagement of an inturned flange 38 on the trip ring withthe stop ring 31.

'Ihe piston 33 is sealed against leakage of fluid in opposite directionsofv its head. Seepage or now in an upward direction'is prevented by acircular sealing ring 39 seated within a V or wedge-shaped groove 40formed on Ethe exterior of 'the nipple 30, this seal or packing engagingthe interior surface of the trip collar or piston. Leakage past thepiston in the other direction is prevented by providing an annularpacking 4I within an internal V or wedge-shaped ring groove 42 formedwithin the trip collar below 'the piston head 34 and tending to urge thesealing ring 4=| into leak proof engagement with the exterior surface ofthe nipple. r

vThe lower end of the main packer body I0 carries a back pressure valveassembly which will permit the free passage of liquid through the en--ti-re device, but which is also capable of causing pressure to be builtup within the .packer for setting it at any place within a casing andfor performing various other functions.- This valve assembly includes aguide cage 43 initially xedly secured to a depending sleeve portion 44ot the rubber retainer 24 by means of one or more shear screws 45.Extending upwardly from the lower portion of this cage is a guide sleeve46 slida'bly receiving a stem 41 secured to the head 48 of the backpressure valve, this head having a tapered end 48a adapted to seat upona seal 49 of rubber or the like provided in the main body. A valvespring 50 encircles the guide and acts against the valve head tonormally urge it to seating engagement with its cooperable seat. Thisvalve head 48 is also positively held against its seat by the engagementof its depending portion 48h with the upper end of .the guide sleeve 46.Such positive seating is desirable to ensure that ports 51 or openingsthrough the valve head will be fully closed by a slidable trip valve 52positioned within the head. 'Ihis slide valve is normally maintainedclear of the ports .by means of a frangible connector in the form of ashear screw 53 secur` ing it .to the main body I0 of the packer.

In the use of the device, the trip assembly is secured to the main bodyof the packer by its threaded interconnection 3|, and the upper vpart ofthe trip nipple is attached to the run-in string of tubing, drill pipe,or the like 54. The packer is lowered in the casing to .the desiredpoint, there being freedom of movement of the displaced huid through thepacker lby its ability to enter the main body through the openings 43ain the valve guide and the radial ports 5I within the backDressure'valve head. Because `of this initial arrangement of valveparts, a swabbing action by in the auxiliary slide valve. Pressure canthereupon be built up within the packer until a force is exerted uponthe ball and slide valve of sucient magnitude to shear the screw 53 andfree the slide valve from the main body, permitting it to be moved intoabutting relationship with the bottom of the back pressure valve head48, and to a position in which Ithe ports 5I are closed. Circulationthrough the packer can then only be obtained by the removal of the backpressure valve head from its cooperable seat.

Initially vthis head is positively held against its seat by the positiveengagement between the head porti-on 48h and guide sleeve, and by therigid securement of the valve cage 43 to the body I0 by the frangiblescrews 45. This arrangement is desirable to ensure that the auxiliaryslide valve 52 will be moved completely downwardly to close the ports 5Ifully, and with its upper end below the sealing tapered surface of thevalve head. If only the valve spring 50 offered resistance .to thedownward movement ofthe valve head, a possibility would exist thatforeign matter or some unforeseen condition would prevent completemovement of the auxiliary slide valve .to its lowermost position,free-from subsequent interference with t'he operation of the 'backpressure valve head.

'I'he building up of pressure Within the 'body after seating of the.ball 55 and shearing of the screw 53, which permits the slide valve tomove to its lowermost position, will produce the shearing of the screwsholding the valve cage 43 in xed position with respect to the body IIIor retainer 24. This action will occur because of the positiveconnection between the slide valve 52 and shear screws 45 afforded bythe abutting of the lower part of .the valve head with the guide sleeve46. As soon as the shear screws fail, the valve spring will move thecage 43 downwardly to a position limited by the engagement of the upperends of guide slots 51 in the cage with guide stops 58 xed to .theretainer sleeve 44. It will be apparent that such lowering of the valvecage will decrease the tension in the spring 54 and remove the abuttingassociation between the valve head and guide, permitting unseating ofthe valve head upon application vthereto of a suflcient pressure toovercome the force of the spring.

Upon seating of the trip ball as described y above (see Figure 2), thebuilding up of pressure in the fluid will cause it to act upon theannular piston 34, and move its collar 33 and associated trip ring 32downwardly against t'he action of 'the return spring 36. In pursuingthis movement, the lower end of the trip ring will abut the upperportion of the ring I2 and move it downwardly against the action of itsassociated return spring I6. The abutment 20 on the cage will engage4the T-shaped heads I4 on the slips and move them downwardly upon theexpander cone 22 to urge the slips radially outwardly until theirwickers I la engage the casing. Thereafter, the running-in string andassociated trip nipple and main body will be moved upwardly (see Figure3), producing a compression of the packing sleeve 25 into sealingengagement with the sides of the casing, and also an upward forceagainst the cone 22, to urge the slip teeth or wickers IIa more firmlyinto the casin-g, ensuring that they will be held therein securely.

The packer is now in position for performing the desired operation orfunction within the casing. If the device is to be used as a cementretainer, .the forcing of the cement slurry down the run-in string andpacker body will unseat the valve head 48, permitting the slurry to passfrom the packer to the desired regions. After sufllcient cement has beenforced through the body, the back pressure valve head will be seated byits associated spring 50 to prevent return flow of any fluid or plasticcement.

The device can be employed also in connection with repressuringoperations, as by pumping a suitable gas through the body and out pastthe back pressure valve, the one-way characteristics of this valvepreventing return ow of the gas. Moreover, formations may be .tested foruid permeability or breakdown pressure through the forcing of a suitablemedium through the packer.

The packer can be left in the casing if desired by rotating the run-instring and trip nipple or sub in a righthand direction, which willproduce a disconnection at the lefhand threads 3I between the sub andthe main body I0 of the packer. However, the present invention includesthe ability to remove the packer after it has been set in position, anda subsequent resetting in the same or another position within the casingwithout the necessity for removing the packer to the surface of thebore.

After the packer has been set and the desired function accomplished, thepressure Within the main body and the trip nipple can be relieved, andthe run-in string and nipple and body connected thereto moved downwardly(see Figure 4) to distend the packing sleeve 25 and move the expandingcone 22 downwardly from contact with the slips II. This will permit thereturn trip spring 36 to move the piston to its initial position andcorrespondingly move the trip ring 32 from engagement with the cage I2,allowing the energy previously stored in the retractor spring I6 to movethe cage upwardly and the slips out of engagement with the casing andfree from functional cooperation with the tapered surface 23 of thecone. An encircling coil spring 59 engagging within a circumferentialgroove 60 in each of the slips is provided to move them radiallyinwardly upon the removal of the cone from its operative position.

The run-in string can now be raised or lowered to position the packer atany other desired point within the casing, after which the pumps can bestarted and pressure built up to move the piston 34 downwardly and causeits associated trip ring 32 to engage the cage I2 and force the slips II downwardly upon the expanding cone 22 into engagement with the casing.Upon taking a strain on the run-in string the packing sleeve .25 canagain be compressed to engage with the casing, and its associated coneurged more strongly against the slips. 'Ihe device is now in conditionfor performing the desired function at its new location.

The packer can again be released and set at another position. 'I'hisability to be alternately set and released permits its utilization as aninstrument for testing casing for holes or fractures, simply by settingthe packer at various positions within the casing and thereafterapplying pressure until the defect in the casing is noted through theinability to build up sufficient pressure within the run-in string andpacking device.

After shearing of the screws holding the back pressure valve guide orcage to the retainer sleeve, the valve spring will limit the effectivepressure upon the annular piston 34, and conse- `cluently limits theforce that can be exerted downwardly upon the slips. This total force isa function of the unit pressure differential in the region of the pistonand the piston area on which uid can act. Heretofore, such annularpistons have been of an unrequired large area, which would undulymultiply the downward force exerted upon them, and which in someinstances might cause an undesired setting of the slips, as, forlexample, upon raising of the packer in the casing. en this operation isperformed, the tubing or drill pipe might extend a hundred feet or moreabove the surface of the bore, the uid coni-ined therein creating asufficient pressure differential to move the piston downwardly to setthe slips. The piston area has previously been of a large size becauseof the necessity for effecting a proper seal between it and itsrelatively stationary cooperable part, as the trip nipple or sub 30 ofthe instant application. Usually a U-shaped or similar sealing ring hasbeen employed at the head of the piston. In the present invention, it isproposed to produce the sealing action at a point remote from thepressure active surface of the piston, and to employ a seal of suchcharacter as to require a minimum of radial space in effectivelyperforming its required functions.

Referring to the drawings as heretofore described, annular seals areprovided on opposite sides of the piston head 34, the sealing rings 39,4I being circular in cross-section, and cooperable with the taperedsides of their confining grooves 4D, 42. 'I'he removal of these sealingelements from the active head of the piston permits the reduction of thepiston area to any desired radial dimenison, which can be as low as thatactually needed to move the slips downwardly against the action of thesprings 36, I6. In sliding of the rings 38, 4I upon the nipple 30 orcollar 33. an effective seal is obtained because of the tendency of eachrubber or leather packing ring to move axially of the wedge groove intoa longitudinally converging space between the groove and its opposedmember, causing a compression of the rings into intimate sealingengagement between the piston or trip collar and the nipple.

We claim:

1. In a device of the character described, the combination of a bodyadapted to be positioned within a well casing, slips carried by saidbody, an expander slidably carried by said body for moving said slipsinto engagement with said casing, an elastic packer xed to said expanderand to said body, and hydraulically actuated means for moving said slipslongitudinally along said expander` into contact with the casing.

2. In a device of the character described, the combination of a bodyadapted to be positioned within a well casing, slips carried by saidbody, an expander slidably carried by said body for moving said slipsinto engagement with said casing, an elastic packer surrounding saidbody and fixed to said expander, and hydraulically actuated means formoving said slips longitudinally along said expander into contact withthe casing independently of any movement of said expander.

3. In a device of the character described, the combination of a bodyadapted to be positioned within a well casing, slips carried by saidbody, an expander slidably carried by said body for moving said slipsinto engagement with said casing, an elastic packing surrounding saidbody and xed to said expander on one side thereof,- and hydraulicallyactuated means on the other side of said expander operable to move saidslips longitudinally along said expander into contact with the casing.

4. A well packer, including body means adapted to be positioned within awell casing, slips carried by said body means, an expander carried bysaid body means for moving said slips into engage'- ment with saidcasing, hydraulically operated means for moving said slips intoengagement with said expander, comprising an annular piston surroundingsaid body means, said piston being provided with a ring groove below itshead, and a sealing ring in said groove engageable with said body means.

5. A well packer, including body means adapted to be positioned within awell casing, slips carried by said body means, an expander carried. bysaid body means for moving said slips into engagement with said casing,hydraulically operated instrumentalities for moving said slips withrespect to said expander, comprising annular piston means surroundingsaid body means, one of said means being provided with a ring groove inits side wall, and a sealing ring in said groove engageable with theother of said means.

6. A well packer, including body means adapted to be positioned within awell casing, slips carried by said body means, an expander carried bysaid body means for effecting movement of said slips into engagementwith said casing, hydraulically operated instrumentalities for producingrelative movement'between said slips and expander, comprising annularpiston means surrounding said body means, one of said means beingprovided with a ring groove in its side wall, and a sealing ring in saidgroove engageable with the other of said means.

7. A Well packer, including body means adapted to be positioned within awell casing, slips carried by said body means, an expander carried bysaid body means for moving said slips into engagement with said casing,hydraulically' operated means for moving said slips with respect to saidexpander,l comprising an annular piston surrounding said body means,said piston having a head and being provided with a ring groove belowsaid head, a sealing ring in said groove engageable with said bodymeans, said body means being provided with a ring groove above saidhead, and a sealing ring in said body groove engageable with saidpiston.

8. A well packer, including body means adapted to be positioned within awell casing, slips carried by said body means, an expander carried bysaid body means for moving said slips into engagement with said casing,hydraulically operated instrumentalities for moving said slips withrespect to said expander, comprising annular piston means surroundingsaid body means, one of said means being provided with a ring groove,and a sealing ring in said groove engageable with the other of saidmeans, said groove havingtapered side walls for urging said sealing ringradially against the other of said means upon relative longitudinalmovement therebetween.

9. A well packer, including a body adapted to be positioned within awell casing, slips carried by said body, an expander carried by saidbody for moving said slips into engagement with said casing,hydraulically operated means for moving said slips with respect to saidexpander, and a detachable connection between said body andhydraulically operated means permitting their disconnection while in thecasing.

10, A well packer, including a body adapted to -be positioned within awell casing, slips carried by said body, an expander carried by saidbody for moving said slips into engagement with said casing,hydraulically operated means for moving said slips with respect to saidexpander, comprising a complementary body, piston means and spn'ng meanscarried by and between said complementary body and piston means, saidcomplementary body being detachably secured to said inst-mentioned bodyto permit its disconnection therefrom while in the casing together withsaid piston means and spring means.

11. A well packer, including a body adapted for positioning within awell casing, slips carried by said body, an expander carried by saidbody for moving said slips into engagement with said casing, springmeans normally urging said slips away from said expander, meanscomprising a piston for moving said slips into engagement with saidexpander, and spring means for moving said piston away from said slips.

12. A well packer, including a body adapted for positioning within awell casing, a plurality of slips disposed circumferentially around saidbody, a ring mounting said slips, an expander carried by said body formoving said slips into engagement with said casing, a spring supportedon said bodyfor urging said ring away from said expander, meansengageable with said ring for moving it toward said expander, and asecond spring for moving said means away from said ring. 1

13. A well packer, including a body adapted for positioning Within awell casing, a plurality of slips disposed circumferentially around saidbody, a ring mounting said slips, an expander carried by said body formoving said slips into engagement with said casing, a spring supportedon said body for urging said ring away from said expander, a nippledetachably secured to said body, apiston slidable on said nipple andengageable with said ring for moving it toward saidexpander, and asecond spring supported on said nipple for moving said piston away fromsaid ring.

14. A well packer, including a body adapted for positioning within awell casing, a plurality of slips disposed circumferentially around saidbody, a ring mounting said slips, an expander carried by said body formoving said slips into engagement with said casing, a spring supportedon said body for urging said ring away from said expander, nipple meansdetachably secured to said body, piston means including a head slidableon said nipple and engageable with said ring for moving it toward saidexpander, a second spring supported on said nipple for moving saidpiston means away from said ring, one of said means having a generallywedge-shaped ring groove below said head confining a sealing ring forengagement against the other of said means.

15. A back pressure valve, including a valve seat, a valve head, meanspositively holding said head against said seat, and' means yieldablyurging said head against said seat upon rendering said positive holdingmeans ineffective.

16. In a well packer, a valve seat, a valve head, means including afrangible connector for positively holding said head against said seat,and.

means yieldably urging said head against said seat upon failure of saidconnector.

1'?. In a well packer, a body through which uid is adapted to pass, avalve seat on said body, a valve head having av port therein permittingpassage of uid, means positively holding said head against said seat,and a valve adapted to close said port, whereby to prevent passage offluid therethrough.

18. In a well packer, a bodythrough which iluid is adapted to pass, avalve seat on said body, a valve head having a port therein permittingpassage of uid from said body, means yieldably holding said head againstsaid seat, and a valve adapted to close said port, whereby to preventpassage of fluid therethrough.

19. In a well packer, a body through which fluid is adapted to pass, avalve seat on said body, a valve head having a port therein permittingpassage of fluid from said body, means positively holding said headagainst said seat, means yieldably urging said head against said seat,and a valve adapted to close said port whereby to prevent passage oriluid therethrough.

20, In a well packer, a body through which iluid is adapted to pass, avalve seat on said body, a valve head having a port therein permittingpassage of fluid from said body, means positively holding said headagainst said seat comprising a frangible connector, a spring engageablewith said means for yieldably urging said head against said seat, aslide valve within said valve head to close the port therein, and afrangible connector securing said slide valve to said body to maintainit clear of said port.

21. In a well packer, a body through which iluid is adapted to pass, avalve seat on said body, a valve headhaving a port therein permittingpassage of fluid from said body, a guide for said head, a frangibleconnector securing said guide to said body to positively hold said headagainst said seat, a spring carried by said guide for yieldably urgingsaid head against said seat, a slide valve within said valve head toclose the port therein, a frangible connector securing said slide valveto said body to maintain it clear of said port, and a lost motionconnection between said guide and body permitting limited movement ofsaid guide away from said head upon failure of said first-mentionedfrangible connector.

22. In a well packer, a body through which iluid is adapted to pass, avalve seat on said body, a valve head, a guide for said head, afrangible connector securing said guide to said body to hold said headpositively against said seat, a spring carried by said guide foryieldably urging said head against said seat, and a lost motionconnection between said guide and body permitting limited movement ofsaid guide away from said head upon failure of said irangible connector.

23. In a well packer, a body through which fluid is adapted to pass, avalve seat on said body,

a valve head, a guide for said head, frangible means securing said guideto said body to hold said head positively against said seat, and meanscarried by said guide for yieldably urging said head against said seatupon failure of said frangible means.

24. In a device of the character described, the combination of a bodyadapted to be positioned within a well casing, initially retracted meansadapted to engage said casing, means coupling said initially retractedmeans to said body both While retracted and in engagement with thecasing, expander means slidably carried by said body for moving saidinitially retracted means into engagement with said casing, andhydraulically operated means for moving said initially retracted meansinto engagement with said expander means.

25. In a device of the character described, the combination of a bodyadapted to be positioned within a well casing, an expander slidablycarried by said body, slips cooperable with said expander for anchoringsaid body to said well casing,

hydraulically actuated means for moving said slips along said expanderinto contact with the casing independently of movement of said expander,and means coupling said slips to said body while they are anchored tothe casing.

26. In a device of the character described, the combination of a bodyadapted to be positioned in a well casing, an expander slidably carriedby said body and having a downwardly diverging outer surface, slipscooperable with said expander for anchoring said body to said wellcasing, hydraulically actuated means for moving said slips downwardly totheir fullest extent along said expander surface into contact with thecasing, and means coupling said slips together and to said body whilethey are anchored to the casing.

27. In a device of the character described. the combination of a bodyadapted to be positioned in a well casing, an expander slidably mountedon said body, normally retracted slips cooperable with said expander foranchoring said body to said well casing, hydraulically actuated meansfor moving said slips along said expander into in a well casing, anexpander slidably mountedv on said body, normally retracted slipscooperable with said expander for anchoring said body to said wellcasing, hydraulically actuated means for moving said slips along saidexpander into contact with the casing independently of movement of saidexpander, and means for coupling said slips to said body and forremoving them from engagement with said casing to their normallyretracted position.

REUBEN C. BAKER. CLARENCE E. BURT. THOMAS M. RAGAN.

